FXPak Pro

The FXPak Pro (formerly known as the SD2SNES) is a Super Nintendo / Super Famicom cartridge that plays games from an SD card, referred to as a “ROM cart”.  It’s compatible with pretty much the entire SNES library, supports instant load times and includes support for “MSU-1 audio” via its Cyclone V FPGA.

I bought mine from Stone Age Gamer:  https://bit.ly/fxpakpro


The FXPak Pro is the most compatible of all the SNES ROM carts currently on the market. In fact, it’s actually easier to list the incompatible games, which is exactly what Ikari has done on his website: https://sd2snes.de/blog/compatibility


Firmware Download

The latest official Firmware can always be found here:  https://sd2snes.de/blog/downloads


MSU-1 Audio

The FXPak Pro supports something called “MSU-1 Audio”, which stands for ” Media Streaming Unit revision 1″.  It’s a homemade “enhancement chip” created by Near that allows for CD-quality audio on a SNES.

A good way to think of it is like this:  Remember the SegaCD?  The graphics were pretty much the same as the Genesis, but the music played directly off the CD allowing for the music to be extremely high quality.  Also, the extra storage space of a CD allowed for FMV playback, within the restraints of the Genesis’ processing power.  Well, this is essentially the exact same thing, but for the SNES and only for patched roms.

While no physical MSU-1 chip was ever created, the code was integrated into a few emulators, as well as the FXPak Pro, allowing full CD-quality audio through real SNES hardware!!!


Audio Mod for OLD revisions (No FXPak’s or SD2SNES “Pro’s” have ever required this):

All revisions of the SD2SNES starting with “H” and later (and every version of the FXPak Pro) already have a great-sounding audio circuit. If you have Rev.H or newer, you can skip this section. If your version is older, there’s actually a modification you can perform to improve the output. Please scroll down for more info.

There are a few differences in the audio circuit of the SD2SNES revisions:

SD2SNES PCB Revisions A-F have slightly lower audio output.
SD2SNES PCB Revision G was a quick fix for this, boosting MSU-1 audio to the correct levels but introducing some noise.
SD2SNES PCB Revision H (and newer) adds an audio opamp forever fixing MSU-1 audio functionality.

This mod replaces the passive filter between the DAC and the SNES’ analog mixer with with the better circuit from the Rev. H (and newer) that includes a unity gain opamp in order to fix the impedance mismatch that caused muffled and quiet audio in older revisions. Basically, it’s more of a “fix” then an “upgrade”, meant to eliminate the need for boosted audio files (clipping), firmware audio boost in the menu (clipping), and the Rev. G 5V mod (distortion). This finally standardizes the correct MSU-1 audio levels between real hardware and emulators.

Borti4938 has actually created a PCB that allows for a slightly easier way to add the mod. You can order the boards and components from these links (with alternative links for the components):

PCB: https://oshpark.com/shared_projects/1ej3Nrdj

Audio amp: x1 per board:

Capacitor: x1 per board:

Resistors: x2 per board:

Also, here’s the installation instructions: https://github.com/borti4938/SNES-AddOn-PCBs/tree/master/sd2snes_RevH/Installation


Also, Qwertymodo has a guide on his website that shows how to directly add the components on the PCB, without a PCB.  While qwerttymodo himself actually recommends using Borti’s solution, here’s his page for reference: http://www.qwertymodo.com/hardware-projects/snes/sd2snes-dac-upgrade

If you’d like this installation service done for you, check with your trusted modder and see if they already have boards made:


Which MSU-1 ROM’s to Use?

You can get lots of MSU-1 patches for SNES roms at http://www.romhacking.net/.  You can also check the Zeldix forums.


Cheap Clones

The SD2SNES is an open-source project and can be made by anyone. That being said, there are a few low-quality clones out there with problems that range from gitchy use, to no MSU audio, to it not working at all. I strongly recommend you only purchase an FXPak Pro from a reputable reseller, such as Stone Age Gamer.

One funny thing about the clones I’ve seen – Even though they were made in China, they still say “manufactured by KRIKzz” and “assembled in Ukraine”.


Custom Menu’s

You can now customize the menu of the SD2SNES/FXPak Pro using this tool: http://www.dotsarecool.com/sd2snesimg/  Actually, Smokemonster used it to make a few awesome custom menus, including a RetroRGB one!  Here’s some examples:

If you created menus for older versions of the firmware, you can use this tool to update them:  http://retrorgb.com/sd2snes-theme-updater-tool.html


That’s it for now! Check out the main ROM cart page for more info on all the ROM Cart’s available for each console.


Feel free to head back to the main page to see what else this site has to offer!